Xamarin传统Android项目在Visual Studio 2017上构建但有错误

Question

我在2-3个月前创建了xamarin traditinal android项目，但我需要更新这个项目，但我收到错误;

Severity    Code    Description Project File    Line    Suppression State
Error       The "LinkAssemblies" task failed unexpectedly.
Java.Interop.Tools.Diagnostics.XamarinAndroidException: error XA2006: Could not resolve reference to 'System.Void Android.App.Activity::OnMultiWindowModeChanged(System.Boolean)' (defined in assembly 'Xamarin.Android.Support.Fragment, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null') with scope 'Mono.Android, Version=0.0.0.0, Culture=neutral, PublicKeyToken=84e04ff9cfb79065'. When the scope is different from the defining assembly, it usually means that the type is forwarded. ---> Mono.Cecil.ResolutionException: Failed to resolve System.Void Android.App.Activity::OnMultiWindowModeChanged(System.Boolean)
   at Mono.Linker.Steps.MarkStep.MarkMethod(MethodReference reference)
   at Mono.Linker.Steps.MarkStep.MarkInstruction(Instruction instruction)
   at Mono.Linker.Steps.MarkStep.MarkMethodBody(MethodBody body)
   at Mono.Linker.Steps.MarkStep.ProcessMethod(MethodDefinition method)
   at Mono.Linker.Steps.MarkStep.ProcessQueue()
   at Mono.Linker.Steps.MarkStep.Process()
   at Mono.Linker.Steps.MarkStep.Process(LinkContext context)
   at MonoDroid.Tuner.MonoDroidMarkStep.Process(LinkContext context)
   at Mono.Linker.Pipeline.Process(LinkContext context)
   at MonoDroid.Tuner.Linker.Process(LinkerOptions options, LinkContext& context)
   at Xamarin.Android.Tasks.LinkAssemblies.Execute(DirectoryAssemblyResolver res)
   --- End of inner exception stack trace ---
   at Java.Interop.Tools.Diagnostics.Diagnostic.Error(Int32 code, Exception innerException, String message, Object[] args)
   at Xamarin.Android.Tasks.LinkAssemblies.Execute(DirectoryAssemblyResolver res)
   at Xamarin.Android.Tasks.LinkAssemblies.Execute()
   at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute()
   at Microsoft.Build.BackEnd.TaskBuilder.<ExecuteInstantiatedTask>d__26.MoveNext() MHG.SozumSana.UI

Answer 1

  

错误XA2006：无法解析对System.Void的引用。Android.App.Activity :: OnMultiWindowModeChanged（System.Boolean）＆＃39; （在汇编中定义＆＃39; Xamarin.Android.Support.Fragment，Version = 1.0.0.0，Culture = neutral，PublicKeyToken = null＆＃39;），范围＆＃39; Mono.Android，版本= 0.0.0.0，文化=中立，PublicKeyToken = 84e04ff9cfb79065＆＃39;。

请检查onMultiWindowModeChanged API，它是在API级别24中添加的。正如@MCZ建议的那样，this is a known issue。

您可以尝试更改以下设置：

此外，Android 7.0需要Android JDK 1.8，我认为你可能已经安装了它，因为你可以提前构建你的应用程序，请查看工具中的 Java开发工具包位置 - ＆gt;选项 - ＆GT;你的VS2017的Xamarin。

Answer 2

使用visual studio check linker属性时，它主要设置为＆＃34; None＆＃34;你必须改变它。

并检查TargetAndroidVersion。 （在配置GUI中，这标题为＆＃34;使用Android版本进行编译：＆＃34;）